Obsolescent or old software that companies need to have access-to, in order to exploit valuable data originally created or recorded using that software, typically information in databases, often on mainframes. Commonly an issue in the financial sector, but also present in computer reservation systems, yield management systems, etc. Legacy software can be a significant commercial problem when the software is leased on an annual fee or for a renewable license, especially licenses tied to a particular computer system – some software companies have been know to aggressively use the need for access to the legacy software when pressing new products.